A gene mutation which occurs before birth, phenylketonuria, also referred to as PKU, eliminates or dramatically reduces the body's ability to break down phenylalanine, or PHE, in proteins, according to the Mayo Clinic. Though the Mayo Clinic notes that it is often identified as present soon after birth in most developed countries, PKU can cause serious health problems. Understanding the side effects of being born with PKU can guide parents and caregivers to appropriate treatment choices.
PHE Buildup
The most dominant side effect of a PKU diagnosis is a buildup of PHE in the body, notes Medline Plus. A protein present in many foods, PHE levels need to be maintained at normal levels to prevent brain damage. The BBC notes that children who are started on a low-protein diet immediately after diagnosis may be able to avoid the side effect of PHE buildup in their bodies.
Mental Retardation
The Mayo Clinic reports that undiagnosed PKU is recognizable by the onset of mental retardation in children born with the disease. The high PHE levels that build up in the body cause brain injury, and as a result within a few months to one year after birth, children will begin to have mental development issues according to the National Health Service.
Seizures/Epilepsy
It has been noted by the Mayo Clinic that one common side effect of PKU is seizures. They may manifest as minor tremors and jerking movements of individual limbs to full-scale seizures. According to the BBC, these seizures can progress and develop into a life-long case of epilepsy.
Fair Skin and Hair Coloring
PHE in children without PKU is transformed into melanin for skin and hair coloring. The Mayo Clinic notes that children born with PKU will show a fair hair and skin tone regardless of the appearance of their parents, since their bodies do not produce melanin.
Musty Urine Odor
The BBC and the Mayo Clinic note that children born with PKU have a musty-smelling urine. This smell is caused by a buildup of PHE in the body. The Mayo Clinic notes that this smell can extend from the urine to include the breath and skin of the child.
